FR2971954A1 - Dispensing head for use in spraying installation to dispense fog on e.g. fruits in product display case of shop, has obturator for sealing fog supply pipe inside head, where obturator integrally extends remote from external openings - Google Patents

Abstract

The head (116) has a wall (120) provided with external openings for dispensing fog, and an obturator (126) for sealing a fog supply pipe that supplies fog to the openings. The obturator integrally extends remote from the external openings. The obturator is movable with respect to a controller. The controller is movable with respect to the wall, around an axis perpendicular to a main axis of symmetry (19) of the head. The controller prevents or limits supply of fog to one of the openings while authorizing the supply of fog to the other opening. Independent claims are also included for the following: (1) a spraying installation for a product display case (2) a method for avoiding dispensing of fog by a spraying installation.

Description

The invention relates to nebulization installations for the production of a mist of droplets. It is known to moisten products, such as food products, by diffusing on them a mist of fine droplets of water generated by an ultrasound generator and diffused outside the installation by one or more heads. of diffusion. The installation is part for example of a display or display of fruits and vegetables. Document FR-2 943 042 discloses a head used in such a context. The head comprises a mast and a plug rotatably mounted so as to place in partial or total coincidence the holes of the mast and the plug. When the orifices are in coincidence and the head is fed with the fog, the latter is diffused outside the head through the orifices. By choosing the position of the plug with respect to the mast, the plug can be placed in a closed position which prevents the diffusion of the mist or select the orifices through which the diffusion takes place.

However, given this arrangement, the various configurations of total or partial opening of the head are limited in number. An object of the invention is to increase the number of configurations of total or partial opening of the head, in particular to increase the number of fog diffusion modes offered by the installation, in order to facilitate the adjustment of the fog distribution, for example on the display of fresh products, to vary the diffusion height, for example depending on the load of the display, and to improve the diffusion towards the products. For this purpose, according to the invention, a fog diffusion head is provided for a nebulization installation, which has external fog diffusion orifices and comprises a shutter capable of closing a supply duct inside the head. fog openings extending completely away from the orifices. Thus, the position of the shutter remote from the orifices makes it possible to provide the head with one or more other organs to vary the mode of diffusion. Thus it is possible to provide a dimmer partially or totally depending on the shutter as will be seen later. In addition, thanks to the fact that the shutter is no longer performed at the openings themselves, it can reduce the volume of the shutter and the amount of material that constitutes it to achieve a saving. In addition, the invention facilitates obtaining a sealing of the head to the extent that it is generally easier to perform a shutter at a distance from the holes than directly on them. For example, the latter, in the document FR-2 943 042 cited above, are 2971954 -2- formed in a cylindrical wall that makes it difficult to perform a sealing. For this reason, the invention also makes it possible to reduce the phenomena of dripping on the outside of the head when it is closed, which otherwise render the installation unhygienic in appearance. Indeed, since the shutter 5 extends away from the orifices in the invention, each of these can, in the closed position of the head, communicate with an internal cavity of the head or with another of the orifices via the inside of the head so that a possible flow takes place inside the head and no longer outside. Advantageously, the head comprises an inverter capable of preventing or restricting the fog supply of one or more orifices while allowing the fog supply of at least one of the orifices. Thus, such a drive can be arranged to allow to choose the one or those sides of the head through which the fog diffusion takes place. It can also make it possible to choose, by a partial coincidence of the orifices of the variator with the external orifices of the head, dimensions of the openings through which the diffusion takes place. This drive can be provided as partially or completely independent of the shutter, it can offer complete freedom in the choice of holes that are open when the head diffuses fog. In one embodiment, the head is arranged so that the variator 20 is adapted to prevent or restrict the supply of one or more of the orifices extending away from this orifice or these orifices. However, it can be provided that the head is arranged so that the drive is able to prevent or even restrict the supply of one or more orifices adjacent to this orifice or these orifices. Advantageously, the variator is movably mounted relative to a wall of the head having the orifices, about an axis perpendicular to a main axis of symmetry of the head. This is a configuration of the variator that allows sometimes to close any side of the head to limit the spread of fog to the other side, sometimes to completely clear all the holes to allow diffusion of fog by each of these. In some embodiments, the shutter is movable relative to the drive, in particular being mounted movably relative to the latter. It can be provided that the head comprises: - a wall having the orifices, and - a cap closing an upper opening of the head, at least one of the shutter and the variator being connected to the wall via the cap 2971954 -3 and / or comprising the cap. Advantageously, the shutter and the variator are connected to the wall via the cap. Preferably, each orifice is oriented towards a base of the head, in particular downwards. Indeed, the heads of the document FR 2 943 042 mentioned above do not always distribute the fog optimally because the jets are oriented upwards with a significant vertical speed component. As a result, a large part of the fog mixes with the ambient air before reaching the products to be moistened. With the aforementioned preferred orientation of the orifices, the jets are directed towards the products so that the fog reaches them before having too much mixed with the ambient air. The humidification of the products is therefore better. Advantageously, the head has a general shape widening from a base of the head to the orifices, the shape being preferably flared. Indeed, with the head of the document FR 2 943 042 mentioned above, there is sometimes an insufficient quality of humidification products due to the cylindrical shape of the head. Here, the advantageous shape of the head makes it possible to reduce the speed of the fog before its expulsion through the orifices. Indeed, the decay of the speed is proportional to the ratio of the square of the diameter of the head in its widest part to the square of the diameter of the supply duct from the head to its base. This ratio is for example of the order of 6 in the configurations described below. In addition, this widening, for example by means of a flared and curved shape of the head, allows the diffusion holes to be oriented downwards. Advantageously, the external orifices have an elongate shape in a radial plane to a main axis of the head. It is found that this form directs the fog further downwards and towards the products. Also provided according to the invention is an assembly for a fog diffusion head of a nebulizing installation, which comprises a head according to the invention, the shutter being removably mounted in a position of the head capable of being occupied by the drive. Thus, if the shutter is installed in the head, any broadcast is prohibited. If the drive is installed in place of the shutter, it allows diffusion only through the selected orifices. This embodiment devoid of mechanism at the drive is particularly simple to achieve. According to the invention, a combination of a mast and a head according to the invention is also provided which is movable, in particular sliding, with respect to the mast between a position in which the shutter closes the mast in the head and a position in which the mast is in communication with the orifices of the head. Thus, the shutter is made directly on the mast. Also provided according to the invention is a nebulizing installation, such as a product display, which comprises at least one head, at least one set or at least one combination according to the invention, the installation further comprising at least a fog generator able to feed the head in fog. Preferably, the generator comprises an ultrasonic transmitter equipped with an acoustic concentration nozzle. The nozzle offers greater diffusion power and allows greater smoothness of the fog, as well as better performance. Finally, according to the invention, there is provided a method for preventing fog diffusion by a nebulisation installation, in which process, in a head having external fog diffusion orifices, a fog orifices supply duct is closed. means of a shutter extending away from the orifices. It is possible to provide closure by moving the head relative to a portion of a mast carrying the head, preferably by sliding in a longitudinal direction of the mast. The mist may be formed of water droplets, or an aqueous solution or another liquid, such as alcohol or gasoline. It may be a mist of a fragrant or disinfectant liquid. Other features and advantages of the invention will become apparent in the following description of several embodiments given by way of non-limiting example with reference to the accompanying drawings, in which: FIG. 1 is a perspective view of a display unit forming a nebulization installation according to the invention, the following figures of which show several embodiments; - Figures 2 and 3 are two exploded perspective views of a head of a first embodiment of the plant respectively in two configurations of the head; Figure 4 is a sectional view of the head in the configuration of Figure 3 in the assembled state; FIGS. 5 and 6 are two perspective views of the shutter and the variator respectively of FIGS. 2 and 3; Figure 7 is a perspective view of the cap of the head of Figures 2-4; - Figures 8 and 9 are two views respectively in perspective and in axial section of a head according to a second embodiment of the installation in the diffusion position; Figures 10 and 11 are views similar to Figures 8 and 9 showing the head in the closed position; FIGS. 12 and 13 are two perspective views of the variator of the head of FIG. 8; FIGS. 14 to 17 are views in perspective and in axial section of a variant of the head of the second embodiment in the closed position; - Figures 18 to 20 are perspective views respectively of a piece forming the cap, the shutter and an operating key of the head of Figure 14; - Figures 21 and 22 are perspective views respectively in the assembled state 15 and in the exploded state of a head according to a third embodiment of the installation according to the invention in the raised position of the shutter; - Figure 23 is a view similar to Figure 21 showing the head in the lowered position of the shutter; - Figure 24 is an axial sectional view of the head of Figure21; Figures 25 and 26 are partial views respectively in axial section and in elevation of a part of the mast of the installation of this embodiment; and FIG. 27 illustrates four respective positions of the head on its mast during use of this installation.

Presentation of the installation FIG. 1 illustrates a nebulization installation 2 for the diffusion of a mist 4 formed of droplets of water of very small size, for example of approximately 5 μm. The installation is in this case a display of products that are here fresh food products. It can be fruits, vegetables, cheeses, meats, fish, flowers or bottles of wine. Installation 2 can be provided in a store to offer the products for sale. It can also be provided in a place of storage or production, for example a place of wine making or cheese refining. The installation can also be used to disinfect products or volumes. It can be used for the disinfection or humidification of products circulating on a carpet for example. The installation 2 comprises one or more displays 6 on which are placed the products to be moistened. It comprises a control and control unit 8 and one or more droplet generators 10 provided in the present example with an ultrasonic transmitter equipped with an acoustic concentration nozzle for the production of fog. Each generator is supplied with water by a suitable means. Such a generator is known in itself, in particular from FR-2 788 706 and will not be described further. The installation comprises a set of ducts 12 by means of which the fog produced by the generator or generators is transmitted to the inside of at least one mast 14 carrying in this case at its upper end a diffusion head 16 having external ports 18 through which mist is sent over the display to the products. The head extends indeed higher than the products to be nebulized and generally has a symmetrical shape of revolution about an axis 19 which is also the longitudinal axis and the axis of symmetry of revolution of the mast 14. We will describe in the following several embodiments of the head 16. In these different modes, the homologous elements will have numerical references simply increased by 100.

First embodiment. A first embodiment of the head 116 is illustrated in Figures 2 to 7. The head comprises a body 120 formed in this case by a bowl whose wall has a section in a radial plane to the axis 19 in a form. arc of circle whose center of curvature is inside the bowl. The bowl has a flared and curved shape, its diameter widening from the base of the bowl to its upper edge. Here, this form divides by 6 the speed of the fog between its entry and its exit from the head, creating a relaxation of the fog, and allows to orient the orifices 18 downwards. The bowl 120 has at its lower end a flange 122 through which it is threaded onto the upper end of the mast with the head coaxial with the mast. The bowl 120 has an upper opening extending in a plane perpendicular to the axis 19, which can be closed by a cap or cap 124 and sealingly as shown in Figure 4. The bowl has orifices 18 passing through its wall from side to side from the outside to the inside of the bowl. These orifices are here six in number but this number can be varied and be for example equal to 2, 3, 4 or 5 or even greater than 6. The orifices are in this case identical to each other and regularly distributed around of the axis 19. Each orifice here has an oblong, slotted shape extending in a direction lying in a plane radial to the axis 19. The axis of each orifice is inclined with respect to the directions vertical and horizontal. As illustrated in Figures 2 and 5, the head may be equipped with a shutter 126 having a cylindrical central body 128 of circular section in a plane perpendicular to the axis of the cylinder. The outer and inner diameters of the body 128 correspond substantially to those of the mast 14. The shutter 126 further comprises two wings 130 extending from the outer face of the body 128 being diametrically opposed to each other. on both sides of the latter. The wings 130 each have a planar shape and extend in a radial plane to the axis of the body 128, this plane being in the species common to both wings. Each flange 130 has a curved lower edge 132 having a male shape complementary to that female of the profile of the internal face of the bowl 120. They have a horizontal rectilinear upper edge 134 started adjacent the body 128 by a cutout 136. 15 The shutter 126 is configured so that it can be arranged as shown in Figure 4 coaxially with the mast, the bowl and the cap so as to extend in the extension of the mast. In this position, the upper edge of the body 128 enters a corresponding female circular groove 136 formed in the wall of the cap. Likewise, the upper edge 134 of the wings penetrates into a radial groove 138 similarly arranged in the cap. The grooves 136 and 138 are dimensioned so that, once the shutter thus inserted into the grooves, it is rigidly immobilized by friction with respect to the cap 124. Preferably, the wings, made of metal, have a left shape and are thus immobilized by jamming in the grooves 138. In addition, the cap tightly closes the body 128. In this position also, the lower axial end of this body is in contact with the wall of the bowl so as to achieve a sealed junction between the central body 128 and the mast 14. The enclosure 140 delimited inside the body 128 is thus closed in the upper part by the cap and in communication only with the mast. The wings 130 extend into the bowl. It is not necessary that they realize by their lower edge 132 a tight junction with the inner face of the bowl even if this can be envisaged. In this configuration, the head 116 is closed, no diffusion of the fog reaching the head through the mast 14 being possible to the orifices 18, taking into account the presence of the shutter and the cap. The head can take another configuration illustrated in FIG. 3. In this one, the obturator 126 which is removably received in the bowl and the cap 2971954 is replaced by a selector or variator 142 illustrated in particular in FIG. Figure 6. The drive has in this case the shape of the shutter 126 which would have removed half the cylinder bounded on one side of the two wings. It thus comprises a central body 144 formed by a half-cylinder carrying at its longitudinal edges two wings 146 identical to the wings 130. The variator 142 is arranged in place of the shutter, the upper edge of the body 144 and wings 146 penetrating the grooves 136, 138 so as to achieve a rigid attachment by friction or jamming of the variator 142 to the cap 124. The wings make a sealed contact by their lower edge 132 10 with the inner face of the bowl. This time, the variator 142 delimits inside the bowl two disjointed and preferably sealed enclosures with respect to each other, namely on the one hand an enclosure that communicates with the interior of the body 144 and the mast and an enclosure isolated therefrom. The external orifices 18 contiguous with the first enclosure 15 are thus in communication with the mast and supplied with fog by the latter. The diffusion of fog by the head is therefore done only by means of these orifices. As for the orifices contiguous to the other enclosure, they are not supplied with fog. Indeed, the wings 146 making a tight contact with the inner face of the bowl and the upper portion of the variator with the cap 20 so that the drive prohibits communication between these orifices and the mast. The cap 124 has on its periphery a shoulder 150 through which it enters the bowl and bears against the upper end of the latter. This shoulder ensures a tight closure of the opening and serves as a guide means to allow the cap 124 to occupy any position relative to the bowl about the axis 19. The cap has a projection of its upper face a relief operating device 152 such as a handle. It is therefore possible by means of this last to orient the cap and therefore the variator 142 to choose those of the orifices through which is carried out the diffusion to the outside of the head, that is to say that of the sides of the head which diffuses the fog. It is not mandatory that the two enclosures be perfectly sealed because, even in the presence of leaks, the amount of fog that would pass through the orifices supposed not to diffuse will be marginal anyway. Indeed, the condensing fog deposits a film of water between the pieces which is sufficient for the most part to achieve the seal. In addition, the air pressure being low, this film resists. It is only preferable to avoid the formation of large drops or to ensure that these drops are directed towards the inside of the tube. Depending on the circumstances, the shutter 126 or the dimmer 142 are thus mounted in the bowl by means of mounting and then reassembling the cap. The bowl, the shutter 126 and the variator 142 are preferably made of metal, for example stainless steel, but it is also possible to produce them in synthetic material. In this mode as in the following, the choice of materials must meet the constraints of use, withstand disinfectants for disinfection and be food grade for applications on fresh consumables. In a variant, it is possible to dispense with the shutter 126 and provide the drive 142 with an internal shutter 126 'having a symmetrical body 10 of revolution received coaxially in the drive. This shutter has been illustrated in FIG. 4, now assuming that it shows the variator 142. The body has a complementary cylindrical outer face of the internal face of the variator 142 and thanks to which it is immobilized rigidly by friction in the body of the variator . It has a conical lower end favoring the dripping of the shutter inside the mast. The height of the shutter 126 'is much smaller than that of the variator 142. The shutter can be placed manually in the low position in the variator, as illustrated in solid lines in FIG. 4 so that the shutter closes the mast 14 at the base of the head to prevent the supply of the fogged or high positions and at a distance from the mast, as illustrated in dashed lines to allow the fog to be supplied with the orifices. This variant avoids removing or adding a piece to the head to intervene on its mode of operation.

Second embodiment.

FIGS. 8 to 13 illustrate a second embodiment of a head of an installation according to the invention. The bowl 220 is substantially identical to that of the first mode. The head 216 comprises an inverter 242, which in this case is in one piece with the cap 224. The variator 242 this time comprises a skirt 244 forming an internal wall approximately conforming to the half of the perimeter 30 of the variator 242. of the internal face of the bowl 220. The skirt 244 has a partial shape with symmetry of revolution, and in a radial plane a profile in an arc. It extends entirely away from the axis 19. The skirt 244 has orifices 252 which are in this case two in number. This number, however, could be reduced to one or equal to three or more. These orifices have an oblong shape homologous to those of the orifices 18 of the bowl. They are in this case open at their lower end, the latter corresponding to the free edge. As in the previous mode, thanks to the flange 250, the cap is rotatable about the axis 19 so as to allow to orient the skirt in any position around this axis relative to the bowl. In this case, the skirt is shaped so that it can be placed in a position in which the two orifices 252 are in register with two consecutive orifices 18 of the bowl, the other orifices 18 of the bowl extending at a distance of the skirt. In this position, the variator does not form an obstacle to the diffusion of the fogger through all the orifices. The head further comprises a shutter 226, which this time occupies the portion of the head near the axis 19. It has a cylindrical outer face 254, 10 circular section in a plane perpendicular to the axis. It is equipped at its top with a maneuvering relief 256 and at its base with a pointed form 258, here configured as a cone. This form allows the concentration of condensed mist on the center of the shutter, the large drops thus formed falling inside the mast without risk of dripping to the outside. The outer face 254 is provided with a complementary thread of a thread formed in a central orifice provided in the cap 224 and in a central flange 258 extending downwardly therefrom. A screw-nut connection is thus made between the cap 224 and the shutter 226 inserted in the cap. The latter can thus occupy with respect to the cap a high position illustrated in Figures 8 and 9 and a low position illustrated in Figures 10 and 11. In this case, the cap has an upper face 260 of concave shape which facilitates access to the relief of maneuver 256 of the shutter. In the high position, the latter extends more protruding from the face 260 in the lower position. Similarly, in the high position, I extends higher than the lower end of the skirt 244 while it extends lower than the latter in the down position. Especially, in the low position, the pointed end 258 of the shutter makes a sealing contact with the lower end edge of the bowl 220 which extends in the axial extension of the upper end of the mast. This contact prevents any communication between the mast and the enclosure defined by the bowl. The orifices 18 are not supplied with fog. On the contrary, in the high position, the tip 258 extends away from the lower end of the bowl 220 so that the enclosure is fed with fog. The orifices 18 which are not otherwise closed by the skirt 244 thus diffuse fog outside the head. In this embodiment, the position occupied by the variator 242 is independent of that occupied by the shutter 226. In particular, it can be provided that the variator places all the orifices 18 in communication with the inside of the bowl, or on the contrary we only part of them, and that the shutter is in the closed position or in the open position. In this embodiment, the shutter 226 and the variator 242 can be made of synthetic material, for example polymer. FIGS. 14 to 20 show an alternative embodiment of this second mode. In this example, the variator242 is no longer made in one piece with the cap 224. They are made of two disjoint pieces which are then assembled to one another rigidly. This arrangement facilitates the manufacture and decreases the material used. In addition, the shutter 226 has no thread on its outer face 254 and instead has a lug 264 which projects radially from this face. Complementarily, the cap 224 provided with the flange has a helical groove 266 formed in the cylindrical inner face of the duct receiving the shutter. This groove 266 receives the lug and thus serves to guide the helicoidal movement of the shutter 226 relative to the variator 242. In addition, the upper end of the helical groove is extended by an arcuate zone extending into a plane perpendicular to the axis 19. This is a bearing that keeps the shutter in the high position at the end of the rotation that allowed him to reach it. Furthermore, this arc being closed at its end, the pin can not escape when the shutter has reached its highest position relative to the variator so that we can continue to rotate the shutter by driving this time the variator242 in the same movement. Starting from the shutter in the closed position as in FIG. 17, it is therefore possible to manipulate the relief 256 to move the shutter to the open position and, once this is reached, to modify the position of the variator by compared to the bowl. In this case, the head is configured so that, from the lower position of the shutter, a rotational movement on the latter makes it go to the high position without the drive moves relative to the bowl. It then occupies a position in which half of the external orifices 18 are closed by the skirt 244 so that the diffusion of the fog outside the head is effected solely by the other orifices, that is to say only on a first half of the head on one side of the axis 19. Continuing the shutter rotation maneuver, it remains in the up position but, the lug being in abutment against the end of the groove the shutter passes the skirt to a position where the outer ports 18 which were initially closed by the latter are now open while those which were left free are closed by the skirt. So this time only the other half of the head that spreads the fog. Finally, the continuation of the rotational movement makes it possible to put the skirt in a position in which it leaves all the external orifices open. These are therefore all sides of the head that allow the diffusion of the fog, which is carried out over 360 °. It can be expected that the entire movement of the shutter is effected on a range as small as a turn and a half, for example. A notch on the bowl and three notches on the variator may be provided to allow the user to identify the three partial and complete open positions mentioned above during the operation of the shutter. Drawings or logos may be affixed to the head to differentiate and clarify these positions. It is observed that the conical tip 258 of the lower end of the shutter has a much larger apex angle, here close to 160 °, than that of the shutter of FIG. 9 which was close to 120. angle should be sufficient to direct the condensates towards the center and eliminate large drops gradually, the surface condition being as important in combination with the angle. The rougher the surface, the larger the angle. In addition, the relief 256 of the shutter here has a hexagonal shape rather than rectangular in plan as in the embodiment of Figure 8. It can be operated by means of a corresponding key 268 as illustrated. In FIG. 20, it may be envisaged to operate the shutter directly by hand without the intermediary of the key 268, but this latter has the advantage of facilitating the maneuvering of the head when it is at a distance from the user. .

In addition, the lower end of the shutter performing the sealing function with the bowl has a greater diameter greater than that of the cylindrical face 254 of the shutter, which therefore generally occupies a smaller volume inside. of the enclosure than was the case in the embodiment of FIG. 8.

Third Embodiment A third embodiment of the head has been illustrated in FIGS. 21 to 27. In this case, the bowl 320 has a spherical shape close to a half-sphere, the upper opening of the bowl extending in an Oan perpendicular to the axis 19, 35 located slightly above the equator. The variator and the shutter are here formed by the same member 326 forming a rigid assembly rotatably mounted relative to the bowl about an axis 370 perpendicular to the axis 19. 2971954 -13- When the latter is vertical, the The axis 370 is horizontal. This articulation is achieved by means of two nipples 372 of the variator which penetrate into two respective notches 374 formed in the bowl to allow a movement of the variator relative to the latter over a quarter of a turn around the axis 370. The variator 326 has a shutter portion 376 shaped as a sphere quarter full of axis 370 and dimensioned so as to extend coaxially with the inner spherical face of the bowl, facing it and at a short distance from the orifices 118, or even in contact with them. This portion 376 has two plane radial faces 377, 378, one of which 377 is extended in the same plane by a flat bottom wall 380. The face 378 and the wall 380 are connected by a flat rib 382 extending in a general plane perpendicular to the axis 370. A maneuvering relief 384 protrudes from the outer face of the rib in a direction radial to the axis 370.

The cap 324 also has a sphere-shaped shape shaped to form a complete sphere as it closes off the top opening of the bowl through the shoulder 350. The lower edge of the cap also includes notches 374 for accommodate the pins 372 and allow the rotation of the variator 326. The cap has a groove 386 extending from the edge of the cap to its top in a plane radial to the axis 370 and accommodating the relief 384 to allow the maneuver of the drive when the cap is in place. The variator can thus occupy a raised position illustrated in particular in FIGS. 21, 22, 24 and 27, and a lowered position illustrated in FIG. 23. In the first, the wall 380 is horizontal and all the orifices 18 are left free by the variator so that the diffusion of the fog by the head can take place through all the orifices 18. In the second, the wall 380 extends in a vertical plane while the portion 376 comes opposite some of the orifices 18 in them. closing. Only the other holes 18 allow the diffusion of the fog.

The dissymmetry of the variator provides a counterweight effect which allows rapid opening or closing, a simple initiation of movement by an operator resulting in a rapid tilt. In this case, the mast 14 is telescopic and comprises for this purpose a lower inner tube 388 and an upper outer tube 390. These two tubes are coaxial, cylindrical and circular in a plane perpendicular to the axis 19. lower tube 388 enters the upper tube 390. The latter carries at its upper end the head 316. In the present example, it is connected to the bowl 320 by a ring 392 penetrating into the respective axial ends of the tube and the bowl while allowing the latter to rotate relative to the tube. Maneuvering the head about the axis 19 can be done by means of a relief 393 extending radially projecting from the base of the bowl with reference to the axis 19.

The inner and outer tubes 388 and 390 are arranged so that the head 316 can diffuse mist to the outside by extending at different heights with respect to the upper end of the lower tube 388 which is assumed fixed relative to the display. . Three diffusion positions have thus been illustrated in Figure 27 on the left, showing the head 316 at different heights.

In the present case, the inner tube 388 has for this purpose two rectilinear grooves 392, parallel to the axis 19 and diametrically opposite on either side of the latter. A shaft 394 is rigidly fixed to two orifices 396 of the external shaft 390 diametrically opposite each other on either side of the axis 19. The shaft 394 also passes through each of the two grooves 392, connecting thus the two tubes to each other. Each of the grooves 392 further has clearances or taps 398, here four in number and starting from the groove laterally downwards being blind. These clearances 398 extend to different respective heights on the same groove but at the same height two by two on the two grooves. They allow to receive the shaft 394 to immobilize the head at a predetermined height with respect to the upper end of the inner tube 388. When the shaft 394 rests on the lower end 400 of the grooves 392, the upper end of the tube The outer wall penetrates into the head and into the bowl 320 into a housing 402 formed in the variator 326, in its lower face when it is in its raised position. This housing being blind, the drive then forms a shutter for the upper end of the inner tube 388. The variator 326 includes for example an O-ring 304 to ensure a good seal between the outer face of the mast and the drive. The fog can not pass from the mast into the part of the chamber 30 delimited in the bowl around the mast so that the head does not diffuse mist through the orifices 18 despite the fact that the drive is in position identified. This position of the head with respect to the inner tube and the display stand is lower than the three aforementioned positions and has been illustrated on the right in FIG. 27. In this embodiment, the variator being in the raised position, it suffices therefore to lowering the head with the outer tube, sliding downward along the axis 19 relative to the inner tube, to penetrate the latter into the head and interrupt the diffusion of fog. Conversely, by raising the head and the outer tube 390 sliding upwards, the communication is restored between the mast and the inside of the head and the possibility of diffusion through the orifices 18. can either leave the variator in the raised position so that the diffusion takes place through all the orifices 18 to 360 °, or place it in the lowered position 5 so that only some of the orifices diffuse the fog. The head then produces 180 ° fog. In this case, it is possible to orient the head thanks to the relief 393 and to choose the direction of diffusion. It can be provided to make the outer tube 390 in a transparent material such as a polymer to visually understand its function and use to the display user. This improves the ergonomics of the latter, especially in the choice of possible settings. The outer mast may be made for example of epoxy, polycarbonate, polyester, polypropylene or polyethylene terephthalate. The cap can be made here again in stainless steel and the variator in polyethylene or polypropylene. The bowl 15 is made for example of stainless steel and the ring 392 in a polymer. The inner and outer tubes can be interchanged, the tube attached to the head becoming the inner tube. This solution presents less risk of leakage. On the other hand, the closing of the arrival of the fog can no longer be done at the level of the head and must take place at the base of the tube, that is to say, more upstream. The latter in low position then comes to close the supply port at the bottom of the installation. It can be alternatively provided that the shutter 326 is rigidly mounted in the head in the raised position, without the possibility of pivoting to a lowered position. It does not serve as a dimmer. In all these embodiments, the water which eventually accumulates by condensation in the head is evacuated by gravity into the mast, for example by flowing from the inner face of the bowl and the skirt and by the spike. the shutter. The height and position of the elongated orifices have their effect. The higher the hole is placed on the head and the shorter it is, the more horizontal and powerful the jet is.

On the contrary, the longer and lower the orifice, the wider the jet is and pointing downwards. Its speed is all the lower as the surface of the orifice is large. The sum of the surfaces of all the orifices is preferably less than the section of the feed duct at the base of the head, in order to maintain a sufficient pressure in the head and to obtain jets sufficiently fast to be insensitive to the currents. ambient air. Of course, we can bring to the invention many changes without departing from the scope thereof. The orifices may have other forms, for example a drop shape, which make it possible to obtain particular effects on the shape of the diffused jets. All variants of orifices are possible to optimize the diffusion, the speed of the jets, their range, the mixing rates and according to the wishes of the user. It is also possible to associate orifices of different shapes, for example long orifices and round orifices. It is also possible to provide successions of round orifices etc. More generally, the shape, number and distribution of the orifices of the bowl and of the variator may be varied as the case may be, depending on the applications and the desired effects. The head can occupy a position such that its main axis is not vertical and is for example horizontal or inclined relative to the vertical direction. The display can include several heads. It can be provided that the mast is itself orientable relative to the display 15 around the axis 19 or slidably mounted relative to the display along this axis. It is also possible to provide motorization means for these movements of the mast, thus making it possible to turn the head in particular. In the third embodiment, any other means for adjusting the height may be envisaged, for example wedges or rings which engage in notches in the tube at regular intervals, ring clamping systems and the like. In all these embodiments, it is possible to provide means for adjusting the height of the mat and therefore of the head. The bowl may be conical or paraboloidal. It can be expected that the head is cylindrical, this form is often less efficient but cheaper. In the first embodiment, the wings could be arranged at an angle different from a half turn around the axis. The wings can be at least 3 or 4. 30

Claims (15)

REVENDICATIONS1. Fog diffusion head (16; 116; 216; 316) for a fogging installation (2), characterized in that it has external fog diffusion ports (18) and comprises a shutter (126; 126 '; 226; 326) adapted to seal the interior of the head a conduit for supplying the fog openings extending completely away from the orifices. 2. Head according to the preceding claim, which comprises an inverter (142; 242; 326) adapted to prevent or restrict the fog supply of one or more orifices (18) while allowing the fog supply of at least one other of the orifices. 3. Head according to the preceding claim, arranged so that the drive (142) is adapted to prevent or restrict the supply of one or more of the orifices extending away from this orifice or these orifices. 4. Head according to at least one of claims 2 to 3, wherein the variator (326) is mounted to move relative to a wall (320) of the head having the orifices, about a perpendicular axis (370). to a main axis of symmetry (19) of the head. The head according to at least one of claims 2 to 4 wherein the shutter (126; 126 '; 226) is movable relative to the variator (142; 242). A head according to at least one of the preceding claims which comprises: - a wall (120; 220) having the orifices (18), and - a cap (124; 224) closing off an upper opening of the head, at least one of the shutter (126; 226) and the variator (142; 242) being connected to the wall through the cap and / or including the cap. 7. Head according to at least one of the preceding claims, wherein each orifice (18) is oriented on the side of a base of the head, in particular downwards. 8. Head according to at least one of the preceding claims, which has a general shape widening from a base of the head to the orifices (18), the shape being preferably flared. 9. Head according to at least one of the preceding claims, wherein the outer orifices (18) have an elongate shape in a radial plane to a main axis (19) of the head. 10. Assembly for a fog diffusion head (116) of a nebulization installation, characterized in that it comprises a head (116) according to at least one of claims 2 to 9, the shutter (126) being removably mounted in a location of the head adapted to be occupied by the variator (142). 5 11. Combination of a mast (14) and a head (316) according to at least one of claims 1 to 9, mounted movably, in particular sliding, relative to the mast between a position in which the shutter (326) closes the mast in the head and a position in which the mast is in communication with the orifices (18) of the head. 10 12. Nebulizing installation (2), such as a product display rack, characterized in that it comprises at least one head (16; 116; 216; 316) according to at least one of claims 1 to 9, at least one assembly according to claim 10 or at least one combination according to the preceding claim, the installation further comprising at least one fog generator adapted to supply the fog head. 13. Installation according to the preceding claim wherein the generator comprises an ultrasonic transmitter equipped with an acoustic concentration nozzle. 14. A method for preventing fog diffusion by a nebulizing installation (2), characterized in that, in a head (16; 116; 216; 316) having external fog diffusion openings (18), a conduit for supplying the fog openings by means of a shutter (126; 126 '; 226; 326) extending away from the orifices. 15. Method according to the preceding claim wherein the obturation is carried out by a displacement of the head relative to a portion of a mast (14) carrying the head, preferably by sliding in a longitudinal direction (19) of the mast. .